Arrhythmia is the disfunction of cardiac normal conduction, which is a life-threatening disease, because it disturbs the rhythmic beating of the heart, worsening hemodynamics. Therefore, therapy for cardiac arrhythmia is clinically essential.
Antiarrhythmic drugs have been grouped together according to the pattern of mechanism: Na channel blocker, Beta blocker, Ca channel blocker and drugs which prolong Repolarization. Drug therapy of cardiac arrhythmias is not established, because many drugs have severe adverse effects, such as undesirable hemodynamic effects, hypotension, gastrointestinal symptoms, effects on the central nervous system and arrhythmogenic effects. Also, at higher plasma concentrations of drug, cardiac toxicity may become severe, so the monitoring of plasma concentration is essential for drug therapy.
It is therefore required to develop new antiarrhythmic drugs having excellent pharmaceutical effects and safety which can be industrially prepared at low cost in a simple manner.